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From: NeilBrown <neilb@suse.de>
To: Chuck Lever <chuck.lever@oracle.com>,
	Jeff Layton <jlayton@kernel.org>
Cc: linux-nfs@vger.kernel.org,
	Olga Kornievskaia <kolga@netapp.com>,
	Dai Ngo <Dai.Ngo@oracle.com>,
	Tom Talpey <tom@talpey.com>
Subject: [PATCH 2/4] nfsd: perform all find_openstateowner_str calls in the one place.
Date: Tue,  5 Mar 2024 09:45:22 +1100
Message-ID: <20240304224714.10370-3-neilb@suse.de>
In-Reply-To: <20240304224714.10370-1-neilb@suse.de>
References: <20240304224714.10370-1-neilb@suse.de>
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Currently find_openstateowner_str looks are done both in
nfsd4_process_open1() and alloc_init_open_stateowner() - the latter
possibly being a surprise based on its name.

It would be easier to follow, and more conformant to common patterns, if
the lookup was all in the one place.

So replace alloc_init_open_stateowner() with
find_or_alloc_open_stateowner() and use the latter in
nfsd4_process_open1() without any calls to find_openstateowner_str().

This means all finds are find_openstateowner_str_locked() and
find_openstateowner_str() is no longer needed.  So discard
find_openstateowner_str() and rename find_openstateowner_str_locked() to
find_openstateowner_str().

Signed-off-by: NeilBrown <neilb@suse.de>
---
 fs/nfsd/nfs4state.c | 93 +++++++++++++++++++--------------------------
 1 file changed, 40 insertions(+), 53 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index b9b3a2601675..0c1058e8cc4b 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -541,7 +541,7 @@ same_owner_str(struct nfs4_stateowner *sop, struct xdr_netobj *owner)
 }
 
 static struct nfs4_openowner *
-find_openstateowner_str_locked(unsigned int hashval, struct nfsd4_open *open,
+find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open,
 			struct nfs4_client *clp)
 {
 	struct nfs4_stateowner *so;
@@ -558,18 +558,6 @@ find_openstateowner_str_locked(unsigned int hashval, struct nfsd4_open *open,
 	return NULL;
 }
 
-static struct nfs4_openowner *
-find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open,
-			struct nfs4_client *clp)
-{
-	struct nfs4_openowner *oo;
-
-	spin_lock(&clp->cl_lock);
-	oo = find_openstateowner_str_locked(hashval, open, clp);
-	spin_unlock(&clp->cl_lock);
-	return oo;
-}
-
 static inline u32
 opaque_hashval(const void *ptr, int nbytes)
 {
@@ -4855,34 +4843,46 @@ nfsd4_find_and_lock_existing_open(struct nfs4_file *fp, struct nfsd4_open *open)
 }
 
 static struct nfs4_openowner *
-alloc_init_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
-			   struct nfsd4_compound_state *cstate)
+find_or_alloc_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
+			      struct nfsd4_compound_state *cstate)
 {
 	struct nfs4_client *clp = cstate->clp;
-	struct nfs4_openowner *oo, *ret;
+	struct nfs4_openowner *oo, *new = NULL;
 
-	oo = alloc_stateowner(openowner_slab, &open->op_owner, clp);
-	if (!oo)
-		return NULL;
-	oo->oo_owner.so_ops = &openowner_ops;
-	oo->oo_owner.so_is_open_owner = 1;
-	oo->oo_owner.so_seqid = open->op_seqid;
-	oo->oo_flags = 0;
-	if (nfsd4_has_session(cstate))
-		oo->oo_flags |= NFS4_OO_CONFIRMED;
-	oo->oo_time = 0;
-	oo->oo_last_closed_stid = NULL;
-	INIT_LIST_HEAD(&oo->oo_close_lru);
-	spin_lock(&clp->cl_lock);
-	ret = find_openstateowner_str_locked(strhashval, open, clp);
-	if (ret == NULL) {
-		hash_openowner(oo, clp, strhashval);
-		ret = oo;
-	} else
-		nfs4_free_stateowner(&oo->oo_owner);
+	while (1) {
+		spin_lock(&clp->cl_lock);
+		oo = find_openstateowner_str(strhashval, open, clp);
+		if (oo && !(oo->oo_flags & NFS4_OO_CONFIRMED)) {
+			/* Replace unconfirmed owners without checking for replay. */
+			release_openowner(oo);
+			oo = NULL;
+		}
+		if (oo) {
+			spin_unlock(&clp->cl_lock);
+			if (new)
+				nfs4_free_stateowner(&new->oo_owner);
+			return oo;
+		}
+		if (new) {
+			hash_openowner(new, clp, strhashval);
+			spin_unlock(&clp->cl_lock);
+			return new;
+		}
+		spin_unlock(&clp->cl_lock);
 
-	spin_unlock(&clp->cl_lock);
-	return ret;
+		new = alloc_stateowner(openowner_slab, &open->op_owner, clp);
+		if (!new)
+			return NULL;
+		new->oo_owner.so_ops = &openowner_ops;
+		new->oo_owner.so_is_open_owner = 1;
+		new->oo_owner.so_seqid = open->op_seqid;
+		new->oo_flags = 0;
+		if (nfsd4_has_session(cstate))
+			new->oo_flags |= NFS4_OO_CONFIRMED;
+		new->oo_time = 0;
+		new->oo_last_closed_stid = NULL;
+		INIT_LIST_HEAD(&new->oo_close_lru);
+	}
 }
 
 static struct nfs4_ol_stateid *
@@ -5331,28 +5331,15 @@ nfsd4_process_open1(struct nfsd4_compound_state *cstate,
 	clp = cstate->clp;
 
 	strhashval = ownerstr_hashval(&open->op_owner);
-	oo = find_openstateowner_str(strhashval, open, clp);
+	oo = find_or_alloc_open_stateowner(strhashval, open, cstate);
 	open->op_openowner = oo;
 	if (!oo)
-		goto new_owner;
-	if (!(oo->oo_flags & NFS4_OO_CONFIRMED)) {
-		/* Replace unconfirmed owners without checking for replay. */
-		release_openowner(oo);
-		open->op_openowner = NULL;
-		goto new_owner;
-	}
+		return nfserr_jukebox;
 	nfsd4_cstate_assign_replay(cstate, &oo->oo_owner);
 	status = nfsd4_check_seqid(cstate, &oo->oo_owner, open->op_seqid);
 	if (status)
 		return status;
-	goto alloc_stateid;
-new_owner:
-	oo = alloc_init_open_stateowner(strhashval, open, cstate);
-	if (oo == NULL)
-		return nfserr_jukebox;
-	open->op_openowner = oo;
-	nfsd4_cstate_assign_replay(cstate, &oo->oo_owner);
-alloc_stateid:
+
 	open->op_stp = nfs4_alloc_open_stateid(clp);
 	if (!open->op_stp)
 		return nfserr_jukebox;
-- 
2.43.0